Docker is an open platform for distributing software application in containers. It utilizes operating system-level virtualization for process and full resource isolation through cgroups, capabilities, SELinux, AppArmor, netfilter, and Linux kernel namespaces. Its libcontainer is based on libvirt and lxc. Docker Engine is the application and environment packaging tool. And Docker Hub is a cloud service for sharing prepackaged containers.

minor bugfix: Networking:
a concurrency preventing network creation.
Runtime:
Relabel secrets path to avoid a Permission Denied on selinux enabled systems (ref.
cases where local volume were not properly relabeled if needed (ref.
an while upgrading if a plugin rootfs was still mounted (ref.
an where volume wouldn't default to the `rprivate` propagation mode (ref.
a panic that could occur when a volume driver could not be retrieved (ref.
Add a warning in `docker info` when the `overlay` or `overlay2` graphdriver is used on a filesystem without `d_type` support (ref.
an with backporting mount spec to older volumes.
where a failed unmount can lead to data loss on local volume remove.
Swarm Mode:
a case where tasks could get killed unexpectedly.
an preventing to deploy services if the registry cannot be reached despite the needed images being locally present.